Dental implement



Patented Aug. 5, 1919.

9 l N2 L V IL [LE S D h m w DnL AN 110 DI EA DC L 60 larger scale,

Dental Implements, of

PERCY RUSSELL, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO ELEGTRO DENTAL MANUFACTURING COMPANY, OF PENNSYLVANIA.

Specification of Letters Patent.

0F PHILADELPHIA, PENNSYLVANIA, A CORPORATION DENTAL IMPLEMENT.

Patented Aug. 5, 1919.

Application filed November 2, 1916, Serial No. 129,249.

To all whom it may concern:

Be it known that I, PERCY RUSSELL, a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented which the following is a specification.

My invention consists of a novel form of dental heating instrument particularly designed for use in drying the root canals of teeth after the extraction of the nerves, softening guttapercha, etc., one object being to provide a compact, efiicient and convenient device having its parts so arranged that itshall satisfactorily perform the work for which it was designed and not be liable to get out of order. It is further desired to" provide an instrument of the class above indicated which shall be of such design as to be capable of highly heating a needle'or point designed for irect application to the member or substance to be treated, while efiectually preventing the material heating of other parts which might cause injury or discomfort to the patient or operator in case of their accidental contact therewith, the construction being such as to permit of the use of a removable needle or point.

Another object of the invention is to provide a novel form of electrical heater particularly designed to raise the temperature mounted metallic point or of a removabl needle to a ingh have its par s so maximum flow of heat to the operating point while preventing its useless dissipation to other parts of the device.

These objects and other advantageous ends I secure as hereinafter set forth, reference being had to the accompanying drawings, in which,

Figure 1 is a side elevation of an instrument constructed according to my invention;

Fig. 2 is an elevation partly in section and on an enlarged scale, further illustrating certain parts of the instrument shown in Fig. 1;

Fig. 3 is degree, and which shall a longitudinal section on a still illustrating the detail construcdisposed as to allow ation of the heating element and its associated parts;

Fig. 4 is transverse section on the line 4-4, Fig. 2; and

Figs. 5 and 6 are fragmentary sections of modified forms of the invention.

In the above drawings, 1 represents a tubular handle usually made of highly polished metal and havin mounted upon it a longitudinally slidable eeve 2 of insulating material. Said tube 1 is provided with a longitudinal slot into which projects the inner end of a screw'3 mounted in the sleeve 2 whereby movement of the latter upon the tube is limited. This screw is held from turning by havin the slot of its head brought into the p ane of a circumferential groove formed in the sleeve 2 for the reception of a spring wire ring 4, which not only fits into said groove but lies within the slot in the head of the screw.

The end of the tube 1 adjacent the sleeve 2 is threaded for the reception of a base or nipple 5 of a poor heat conductor such as bakelite, and this latter has fixed in and projecting beyond one of its ends a metallic tube or terminal 6, being also provided with an extension on which is mounted a'concentric metallic sleeve 7.

Fitting into the nipple 5 and projecting beyond itS,opposite end is a second metallic tube 8 shown in the drawing as composed of a portion 9 of steel and a second portion 10 of silver connected b any desired means such as soldering, we ding or brazing, and of these portions t e first lies within the nipple 5 where it is held by a set screw 11, This latter like the screw be held from turning by a spring wire ring 11' whichpasses through the slot in its outer end and. lies within a circumferential groove in the nipple.

It is noted that the interior surface of the nipple 5 is for the most part spaced away from the part 9 of the sleeve 8 so that the latter is surrounded by an air space except atits inner extremity, which fits tightly into said nipple and is engaged by the set screw 11..

The silver portion 10 of the metal sleeve 3, may if desired 8 is preferably tapered and has fixed concentrlcally within it a tube 12 preferably of copper or silver, which extends to or adjacent the point at which it is connected to the part 9. The greater part of the length of this inner tube is out of contact with and spaced away from the inner surface of the portion 10 of the sleeve so that it also for the most part is surrounded by an insulatin air space. The outer end of the copper s eeve 12 has soldered or otherwise fixed within it a silver plug 13 whose outer end is threaded for the reception of the internally threaded end 14 of an operating needle or point 15 made of metal such as silver of high heat conductivity and tapering from the plug to its extremity ;it being noted that the needle end is more or less flexible and capable of remaining in any form in which it is bent. Obviously other shapes of points or operating tools may be substituted for that shown without departing from my invention.

If desired the joined ends of the tubes 10 and 12 may be swaged or compressed to form a solid end 13, Fig. 5, in place of the plug 13, and the point or tool may be threaded on the structure so pointed. On the other hand as shown in Fig. 6 the inner tube 12 may be extended through the end of the outer tube 10 and be threaded as at 13 for the direct reception of the needle. Within the inner or copper tube 12 I mount a heating element made by wrapping a thin thread or covering 17 of asbestos or other electric insulator, about the heating wire 16 which is usuallymade of platinum and thereafter winding said wrapped wire upon itself in the form of a helix or coil; its two ends ing respectivel connected to conductors 18 and 19 which extend through the part 9 into passages in the threaded end of the nipple 5. In place of this form of heating element I may merel give the insulated wire the elongated U-s1aped form indicated at 16 in Fig. 6. One end of the heating element is electrically connected to the sleeve 7 while the other is similarly connected to the sleeve 6, and by means of a suitable switch within the tube 1, operated by the sliding sleeve 2, as described and claimed in my application for Patent No- 856,940, filed August 15, 1914, these terminals may be respectively connected to conductors leadin to a source of current supply through a ca le20 within said tube 1.

With the above described arrangement, the convolutions of the heating element are completely insulated not only from each other but from the copper tube 12 within which they are mounted, and when current is supplied to said element, it is raised to a high temperature, thereby highly heating the inner tube 12. From the outer end of this latter, heat is conducted through the plug 13 or swaged end 13 or preferably directly as in Fig. 6, to the needle 15, thereby heating it to the temperature required for drying and sterilizing the root canals of teeth, or for other purposes. If the needle be employed for such operations as eauterizing, its proportions as well as those of its associated parts may be varied'to suit the work to be performed.

While the point 16 is highly heated, the part 9 of the tube 8, bein a relatively poor conductor and separatef from the inner tube by an air space, will not materially lower the temperature of said point by a useless dissipation of the heat due to conduction back-to the nipple 5. The part 9'is therefore maintained at a comparatively low temperature and in any case is completely-inclosed b the nipple 5, thus protecting the lips o a patient as well as the fingers of the operator.

By merely bending the pointor needle 15 it may easily be given the shape of the root canal being treated ;it being understood that the term needle is intended to cover any form of surgical instrument or tool designed to have its temperature raised to a high point by heat generated in a heating element.

It will be noted that by the arangement .shown in Fig. 2, it is possible by merely removing the spring locking wire ll and slacking the set screw 11, to separate the tube 8 with its attached point and inner tube 12 from the nipple 5, in which case the electrical conductors 18 and 19 with the heating element are withdrawn intact from said tubes. Moreover, the needle or point may be easily detached from the body of the instrument, it being customary to furnish several needles with each instrument.

I claim 1. The combination of an inner and an outer tube, of which the first is closed and connected to the second tube adjacent one end thereof only; a point to be heated mounted onthe closed end of the first tube; and a heating element within the inner tube.

2. The combination with a solid tapering needle of a heating element therefor, consisting of a loop of wire provided with a non-conducting covering; with a metal tube closely surroundin said heating element and mechanically but separably connected to the point.

3. The combination of a tube; a point mounted on one end thereof; a heating element in said tube adjacentsaid end; with a nipple of low thermal conductivity mounted on the opposite end of the tube and having a portion spaced away from the external surface of said tube.

4. The combinaton of a tube; a point mounted on one end thereof; a heating element in said tube adjacent said end; a nipple of non-conducting material mounted on the opposite end of the tube; terminals on said nipple; and electric conductors extending from the heatin element through the tube to said termina s.

5. The combination of an inclosing tube;

a second tube connected to one end thereof and extending into the same, with its surface spaced away from the interior surface of the first tube; an insulated heating wire extending within said second tube; with a point connected to said tubes in position to receive heat from said wire when the latter is supplied with current.

6. The combination of a nipple of insulating material; terminals mounted thereon; a heating element connected to said terminals; with a tube detachably connected to said nipple and inclosing said element, there being an air space between the tube and a portion of the interior wall of the nipple.

7. The combination of a nipple of insulating material; terminals mounted thereon; a heating element connected to said telminals; a tube detachably connected to said nipple; a second tube within the first tube and inclosing said heating element; there being an air space between the outer tube and a portion of the interior Wall of the nipple.

8. The combination of a nipple of insulating material; terminals mounted thereon; a heating element connected to said terminals; a tube detachably connected to said nipple; a second tube within the first tube and inclosing said heating element, there being an air space between the outer tube and a portion of the interior wall of the nipple and a second air space between the two tubes.

PERCY RUSSELL. 

